Filter with improved hardness and filtration efficiency

Abstract

There is provided a smoking article comprising an aerosol generating substrate and a mouthpiece attached to the aerosol generating substrate. The mouthpiece includes a segment comprising a filtration material comprising polylactic acid, and an additive for reducing phenols. The mouthpiece further comprises one or more wrappers circumscribing the segment, the one or more wrappers have a combined basis weight of at least about 50 grams per square metre (gm-2).

The invention claimed is: 
     
       1. A smoking article comprising:
 an aerosol generating substrate; and 
 a mouthpiece attached to the aerosol generating substrate, the mouthpiece comprising a segment comprising:
 a filtration material comprising polylactic acid; and 
 an additive for reducing phenols; 
 
 wherein the additive comprises a mixture of triacetin with cellulose acetate flakes. 
 
     
     
       2. A smoking article according to  claim 1  wherein the filtration material comprises a plurality of fibres formed at least in part of polylactic acid. 
     
     
       3. A smoking article according to  claim 2 , wherein the fibres are substantially unconnected to one another. 
     
     
       4. A smoking article according to  claim 3 , wherein the filtration material comprises a blend of the polylactic acid and at least one other polymer. 
     
     
       5. A smoking article according to  claim 1 , wherein the filtration material comprises a blend of the polylactic acid and at least one other polymer. 
     
     
       6. A smoking article according to  claim 5 , wherein the blend comprises a blend of the polylactic acid, polyglycolic acid and poly-(L)-lactic acid. 
     
     
       7. A smoking article according to  claim 1 , wherein the additive for reducing phenols is dispersed amongst the filtration material. 
     
     
       8. A smoking article according to  claim 7 , wherein the additive for reducing phenols is the only additive provided in the segment. 
     
     
       9. A smoking article according to  claim 1 , wherein the additive for reducing phenols is the only additive provided in the segment. 
     
     
       10. A smoking article according to  claim 1 , wherein the mouthpiece further comprises one or more wrappers circumscribing the segment, and wherein the one or more wrappers have consists of a single wrapper having a base weight of at least 50 grams per square metre (gm −2 ), or wherein the one or more wrappers consists of a plurality of wrappers, the plurality of wrappers having a combined basis weight of at least 50 grams per square metre (gm −2 ). 
     
     
       11. A smoking article according to  claim 10 , wherein the one or more wrappers comprise a first wrapper, the first wrapper being in direct abutment with the filtration material and having a basis weight of at least 50 grams per square metre (gm −2 ). 
     
     
       12. A smoking article according to  claim 10 , wherein the one or more wrappers consists of a single wrapper having a thickness of at least about 80 μm, or wherein the one or more wrappers consists of a plurality of wrappers, the plurality of wrappers having a combined thickness of at least 80 μm. 
     
     
       13. A smoking article according to  claim 10 , wherein the one or more wrappers consists of a single wrapper having a bending stiffness of at least 0.08 N in a machine direction of the wrapper, or wherein the one or more wrappers consists of a plurality of wrappers, the plurality of wrappers having a combined bending stiffness of at least 0.08 N in the machine direction of the plurality of wrappers. 
     
     
       14. A smoking article according to  claim 1 , wherein the segment has a hardness of at least about 75%. 
     
     
       15. A smoking article according to  claim 1 , wherein the segment has an ovality, after a 50% deformation of the segment, of less than about 25%. 
     
     
       16. A smoking article according to  claim 1 , wherein the filtration material comprises a gathered sheet of material comprising the polylactic acid.